Pressure cook toor dal by adding water and little Curry leaves.Heat oil in a pan and add mustard seeds into it. Allow it to splutter.Add onion, ginger-garlic paste, crushed chilly, turmeric powder and curry leaves and sauté till onions turn translucent.Add tomato slices and sauté for a while .Stir in cooked dal and necessary water and allow it to boil and turn the heat off.Add coriander leaves.Serve with chapattis ,rice, and nan